Re: [Qemu-devel] [PATCH RESEND v1 4/8] target-microblaze: Convert version_mask to a CPU property

["Edgar E. Iglesias" <edgar.iglesias@xilinx.com>]

On Fri, Jun 05, 2015 at 12:53:05PM +1000, Alistair Francis wrote:
> On Fri, Jun 5, 2015 at 12:51 PM, Alistair Francis
> <alistair.francis@xilinx.com> wrote:
> > On Fri, Jun 5, 2015 at 10:42 AM, Edgar E. Iglesias
> > <edgar.iglesias@xilinx.com> wrote:
> >> On Thu, Jun 04, 2015 at 11:23:19AM +1000, Alistair Francis wrote:
> >>> Originally the version_mask PVR bits were manually set for each
> >>> machine. This is a hassle and difficult to read, instead set them
> >>> based on the CPU properties.
> >>>
> >>> Signed-off-by: Alistair Francis <alistair.francis@xilinx.com>
> >>> ---
> >>>  hw/microblaze/petalogix_ml605_mmu.c |    3 ++-
> >>>  target-microblaze/cpu-qom.h         |    1 +
> >>>  target-microblaze/cpu.c             |    4 +++-
> >>>  3 files changed, 6 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/hw/microblaze/petalogix_ml605_mmu.c b/hw/microblaze/petalogix_ml605_mmu.c
> >>> index 5f341c4..f52654c 100644
> >>> --- a/hw/microblaze/petalogix_ml605_mmu.c
> >>> +++ b/hw/microblaze/petalogix_ml605_mmu.c
> >>> @@ -70,7 +70,7 @@ static void machine_cpu_reset(MicroBlazeCPU *cpu)
> >>>
> >>>      env->pvr.regs[10] = 0x0e000000; /* virtex 6 */
> >>>      /* setup pvr to match kernel setting */
> >>> -    env->pvr.regs[0] = (env->pvr.regs[0] & ~PVR0_VERSION_MASK) | (0x14 << 8);
> >>> +    env->pvr.regs[0] |= (0x14 << 8);
> >>>      env->pvr.regs[4] = 0xc56b8000;
> >>>      env->pvr.regs[5] = 0xc56be000;
> >>>  }
> >>> @@ -99,6 +99,7 @@ petalogix_ml605_init(MachineState *machine)
> >>>      object_property_set_bool(OBJECT(cpu), true, "dcache-writeback",
> >>>                               &error_abort);
> >>>      object_property_set_bool(OBJECT(cpu), true, "endi", &error_abort);
> >>> +    object_property_set_bool(OBJECT(cpu), true, "version_mask", &error_abort);
> >>>      object_property_set_bool(OBJECT(cpu), true, "realized", &error_abort);
> >>>
> >>>      /* Attach emulated BRAM through the LMB.  */
> >>> diff --git a/target-microblaze/cpu-qom.h b/target-microblaze/cpu-qom.h
> >>> index 85b8f75..b6c6374 100644
> >>> --- a/target-microblaze/cpu-qom.h
> >>> +++ b/target-microblaze/cpu-qom.h
> >>> @@ -67,6 +67,7 @@ typedef struct MicroBlazeCPU {
> >>>          bool usemmu;
> >>>          bool dcache_writeback;
> >>>          bool endi;
> >>> +        bool version_mask;
> >>>      } cfg;
> >>>
> >>>      CPUMBState env;
> >>> diff --git a/target-microblaze/cpu.c b/target-microblaze/cpu.c
> >>> index f40df43..849c737 100644
> >>> --- a/target-microblaze/cpu.c
> >>> +++ b/target-microblaze/cpu.c
> >>> @@ -115,7 +115,8 @@ static void mb_cpu_realizefn(DeviceState *dev, Error **errp)
> >>>      env->pvr.regs[0] |= (cpu->cfg.stackprot ? PVR0_SPROT_MASK : 0) |
> >>>                          (cpu->cfg.usefpu ? PVR0_USE_FPU_MASK : 0) |
> >>>                          (cpu->cfg.usemmu ? PVR0_USE_MMU_MASK : 0) |
> >>> -                        (cpu->cfg.endi ? PVR0_ENDI_MASK : 0);
> >>> +                        (cpu->cfg.endi ? PVR0_ENDI_MASK : 0) |
> >>> +                        (cpu->cfg.endi ? ~PVR0_VERSION_MASK : 0);
> >>
> >> This looks wrong...
> >>
> >> My guess is that this should be:
> >> cpu->cfg.version_mask ? PVR0_VERSION_MASK : 0
> >
> > So looking at the spec more the version mask should be a two byte
> 
> Woops, I meant one byte number.
> 
> Thanks,
> 
> Alistair
> 
> > number that indicated the version. I can't see it in the DTS,  so I
> > think it should be a settable number, not a bool.
> >
> > I'm not sure why it zeroes it out though,

Aha I see now, the ml605 is forcing the CPU version to "8.00.b".

Shouldn't this prop just be a string with the re-encoding to
version field done by the CPU model?

Cheers,
Edgar


> >
> > Thanks,
> >
> > Alistair
> >
> >>
> >> and that maybe the ml605_mmu board is trying to disable the version mask,
> >> e.g setting it to false.
> >>
> >> Can you double check that it matches with dts and specs?
> >>
> >>
> >>>
> >>>      env->pvr.regs[2] |= (cpu->cfg.usefpu ? PVR2_USE_FPU_MASK : 0) |
> >>>                          (cpu->cfg.usefpu > 1 ? PVR2_USE_FPU2_MASK : 0);
> >>> @@ -176,6 +177,7 @@ static Property mb_properties[] = {
> >>>      DEFINE_PROP_BOOL("dcache-writeback", MicroBlazeCPU, cfg.dcache_writeback,
> >>>                       false),
> >>>      DEFINE_PROP_BOOL("endi", MicroBlazeCPU, cfg.endi, false),
> >>> +    DEFINE_PROP_BOOL("version-mask", MicroBlazeCPU, cfg.version_mask, false),
> >>>      DEFINE_PROP_END_OF_LIST(),
> >>>  };
> >>>
> >>> --
> >>> 1.7.1
> >>>
> >>